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During the twentieth century, inadequate management of mine waste at the Mount Lyell Copper Mine affected the ecology of the Queen–King Rivers and Macquarie Harbour, western Tasmania, Australia. Over the past two decades, the water quality of the river system has been measured semi-annually to investigate the long-term hydrochemical and environmental impacts caused by these historical mine practices and the waste associated with the Mount Lyell mine to the Queen–King Rivers. At sample sites below the confluence of Haulage Creek, the water pH was below pH 3.5, remaining below pH 5 across all sites to Macquarie Harbour. Local baseline rivers ranged from pH 4.0 to 8.4. Elemental concentrations of dissolved metals in water samples downstream of Haulage Creek were above the Australian and New Zealand Environment and Conservation Council (ANZECC) water quality guidelines. Copper, Fe, and Zn were not attenuated along the length of the river, with concentrations remaining elevated to the King River Delta. Mineralogical analyses demonstrated secondary minerals in sediments at Haulage Creek and pyrite concentrated at the King River Delta. Static tests on mining-affected sediments indicated risk of AMD and metal(loid) leaching in the river system. Since 2016, after flooding of the Prince Lyell mine, dissolved metal levels in the Queen–King Rivers have decreased; however, concentrations remain above guidelines. Almost three decades after legacy mine waste disposal ended, it still poses a long-term risk to the downstream environment, implying that without effective management of these historical mine wastes, the Queen–King Rivers will continue to be severely impacted. [ABSTRACT FROM AUTHOR]

The Devonian Sn-mineralized Heemskirk and barren Pieman Heads granites of western Tasmania (southeast Australia) contain abundant tourmaline-rich features, including orbicules, patches, cavities, and veins within their roof zones. The δ11B and δ18O compositions of tourmaline from these texturally different features range from − 21.7 to + 4.1‰ (average − 4.7 ± 4.0‰, n = 127), and from + 6.5 to + 14.9‰ (average + 10.7 ± 1.8‰, n = 38), respectively. These data suggest that the tourmaline-rich assemblages precipitated mostly from magmatic-hydrothermal fluids derived from their host plutons, mixed with minor external components sourced from metasedimentary, meta-ultramafic rocks, and/or meteoric water. The B-isotopic values increase sequentially from tourmaline patches to orbicules and/or cavities in both granites, probably caused by progressive volatile exsolution and systematic fluxing of aqueous boron-rich fluids from the S-type magmas during emplacement into the shallow crust. High degrees of fractional crystallization of the melt may have caused the exsolution of boron-rich hypersaline fluids from which the tourmaline orbicules and cavities formed. Bimodal δ11B populations (− 21.7 to − 12.7‰ and − 3.9 to + 4.0‰) imply that the granitic melts were mostly sourced from 10B-rich metapelitic rocks. The granites underwent fluid exsolution during the late magmatic stage that contributed to the widespread development of tourmaline-rich features and also to the formation of tin deposits associated with the Heemskirk Granite. [ABSTRACT FROM AUTHOR]